The present disclosure relates to geophones used in oil and gas exploration and extraction and, more particularly, to dual core geophones that include a locking mechanism for the geophone mass to avoid damage and failure of the vibration sensitive mechanism.
In the field of oil and gas exploration and extraction, physical properties of the geological formations traversed by a wellbore are often determined using acoustic sensors. In many instances, it is desirable to obtain information while drilling the downhole, as in a logging while drilling (LWD) or measuring while drilling (MWD) application. Some configurations of acoustic sensors generate shock waves of high intensity to collect acoustic information from the seismic activity following the shock. In these situations, extreme operational conditions affect the acoustic sensor at least in terms of pressure, temperature, vibration and shock. As a result, acoustic sensors tend to have a short lifetime and are prone to malfunction after a short operational period. Attempts to use stronger materials to build the mechanical components of acoustic sensors have resulted in heavier and more complex devices having multiple wires and connectors. However, these ruggedized sensors lack the sensitivity that would be desirable in such extreme conditions.